From Monday, she will take on her most important – governor-general.

Ms Mostyn will be sworn in as Australia’s 28th vice-regal representative in a ceremony at Parliament House, marking the start of her five-year term.

She will be just the second woman to take on the role of the representative of the monarchy, following Quentin Bryce.

Born the eldest of four sisters in Canberra to an army officer father, Ms Mostyn began professional life as a lawyer, working as an associate in the NSW Supreme Court of Appeal.

She briefly worked as a communications advisor to former prime minister Paul Keating in the 1990s before serving on the boards of companies such as Transurban, Virgin Australia and Citibank Australia.

In 2005, she was appointed as the first female commissioner of the AFL and was a driving force behind the establishment of the code’s women’s league.

She has also served on non-profit boards including the Climate Council, Beyond Blue and the Sydney Theatre Company and spent time leading the Women’s Economic Taskforce.

Announcing her appointment as governor-general in April, Prime Minister Anthony Albanese said Ms Mostyn “represents the best of modern Australia”.

“She has lived her life in the service of a powerful Australian principle: when more people have the opportunity to fulfil their potential, our nation is a better place,” he said.

“This understanding has driven Sam’s tireless advocacy for gender equality, particularly in the world of business, for women’s safety and for reconciliation.”

Monday’s swearing-in ceremony in Canberra will begin with an Indigenous smoking ceremony outside Parliament House.

The new governor-general will be sworn in on the floor of the Senate by High Court Chief Justice Stephen Gagler.

Ms Mostyn will take over from David Hurley, who served as the monarch’s representative in Australia since 2019.